Top

1V, Low-Power, DirectDrive, Stereo Headphone Amplifier with Shutdown

Product Details

Key Features

Simplified Block Diagram

Technical Docs

Support & Training

Search our knowledge base for answers to your technical questions.

Filtered Search

Our dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal .

Key Features

  • Low Quiescent Current:
    • 2.1mA (MAX9725A–MAX9725D)
    • 2.3mA (MAX9725E)
  • Single-Cell, 0.9V to 1.8V Single-Supply Operation
  • Fixed Gain Eliminates External Feedback Network
    • MAX9725A: -2V/V
    • MAX9725B: -1.5V/V
    • MAX9725C: -1V/V
    • MAX9725D: -4V/V
  • Adjustable Gain with External Input and Feedback Resistors
    • MAX9725E: Minimum Stable Gain of -1V/V
  • Ground-Referenced Outputs Eliminate DC Bias
  • No Degradation of Low-Frequency Response Due to Output Capacitors
  • 20mW per Channel into 32Ω
  • Low 0.006% THD+N
  • High PSRR (80dB at 1kHz)
  • Integrated Click-and-Pop Suppression
  • Low-Power Shutdown Control
  • Short-Circuit Protection
  • ±8kV ESD-Protected Amplifier Outputs
  • Available in Space-Saving Packages
    • 12-Bump UCSP (1.54mm x 2.02mm x 0.6mm)
    • 12-Pin Thin QFN (4mm x 4mm x 0.8mm)

Applications/Uses

  • Cell Phones
  • MP3 Players
  • PDAs
  • Portable Audio Equipment
  • Smartphones

Description

The MAX9725A–MAX9725D fixed-gain, stereo headphone amplifiers are ideal for portable equipment where board space is at a premium. The MAX9725E offers the flexibility to adjust the gain with external input and feedback resistors. The MAX9725A–MAX9725E use a unique DirectDrive® architecture to produce a ground-referenced output from a single supply, eliminating the need for large DC-blocking capacitors, saving cost, board space, and component height. Fixed gains of -2V/V (MAX9725A), -1.5V/V (MAX9725B), -1V/V (MAX9725C), and -4V/V (MAX9725D) further reduce external component count. The adjustable gain of the MAX9725E DirectDrive headphone amplifier allows for any gain down to -1V/V using external resistors.

The MAX9725 delivers up to 20mW per channel into a 32Ω load and achieves 0.006% THD+N. An 80dB at 1kHz power-supply rejection ratio (PSRR) allows the MAX9725 to operate from noisy digital supplies without an additional linear regulator. The MAX9725 includes ±8kV ESD protection on the headphone output. Comprehensive click-and-pop circuitry suppresses audible clicks and pops at startup and shutdown. A low-power shutdown mode reduces supply current to 0.6µA (typ).

The MAX9725 operates from a single 0.9V to 1.8V supply, allowing the device to be powered directly from a single AA or AAA battery. The MAX9725 consumes only 2.1mA of supply current, provides short-circuit protection, and is specified over the extended -40°C to +85°C temperature range. The MAX9725 is available in a tiny (1.54mm x 2.02mm x 0.6mm) 12-bump chip-scale package (UCSP™) and a 12-pin thin QFN package (4mm x 4mm x 0.8mm).

Simplified Block Diagram

MAX9725: Pin Configuration MAX9725: Pin Configuration Zoom icon

Technical Docs

Support & Training

Search our knowledge base for answers to your technical questions.

Filtered Search

Our dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal .